COREFIR-XX Datasheet, PDF (7/14 Pages) Actel Corporation – CoreFIR Finite Impulse Response (FIR) Filter Generator

CoreFIR
FIR
clk
rstn
datai_en
datai
datao_valid
datao_valid
datao
ready*
coefi_en*
Note: *coefi_en and ready are available when coef_fixed = 0.
Figure 3 • I/O Signals
CoreFIR Generator Parameters
The CoreFIR generates the RTL code for FIR filters with a variety of parameters. These parameters include generic FIR
parameters such as number of taps, number of input’s bits, number of coefficients’ bits, and data type, as well as
implementation parameters such as FPGA family, use embedded RAMs, system clock rate, and data sampling rate. The
CoreFIR supports the variations specified in Table 4.
Table 4 • CoreFIR Generator Configuration Parameters
Recommended Selection
Parameter Name
Description
AX
APA
SX-A
module_name
Name of generated module
–
–
–
nbits_input
Number of input’s bits of data
2 – 24
2 – 24
2 – 24
nbits_coef
Number of coefficients’ bits of data
2 – 24
2 – 24
2 – 24
ntaps
Number of taps
2 – 128
2 – 64
2 – 32
tap
Array of coefficients
–
–
–
data_signed
Data type: 0 = unsigned, 1 = signed
0,1
0,1
0,1
fpga_family
FPGA family
ax
apa
sxa
coef_fixed
0 = filter with configurable coefficients
1= filter with fixed coefficients
–
–
–
sys_clk_frq
sample_ratio
Input clock frequency
Sampling rate = sys_clk_frq/sample_ratio
–
≥ nbits_in
–
≥ nbits_in
–
≥ nbits_in
Module_lang
Reserved. VHDL only.
VHDL
VHDL
VHDL
Refer to "Appendix I: Sample Configuration File" on
page 12 for a sample usage of the parameters shown in
Table 4 in a configuration file for the CoreFIR Generator.
Detailed discussions about these parameters are in the
sections of this datasheet that follow.
Number of Taps (ntaps)
The FIR generator supports the number of taps specified
by the device families in Table 4. The variable ntaps in
the configuration file specifies the setting of this
parameter. Refer to "Appendix I: Sample Configuration
File" on page 12 for details.
Number of Bits of Inputs (nbits_in) and
Coefficients (nbits_coef)
The FIR Generator supports the number of bits of inputs
and coefficients for the device families specified in
Table 4. These parameters are set with the variables
nbits_in and nbits_coef in the configuration file. Refer to
"Appendix I: Sample Configuration File" on page 12 for
details.
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